Darrick J. Wong
048d54100c
[ Upstream commit6ff646b2ce] Keys for extent interval records in the reverse mapping btree are supposed to be computed as follows: (physical block, owner, fork, is_btree, is_unwritten, offset) This provides users the ability to look up a reverse mapping from a bmbt record -- start with the physical block; then if there are multiple records for the same block, move on to the owner; then the inode fork type; and so on to the file offset. However, the key comparison functions incorrectly remove the fork/btree/unwritten information that's encoded in the on-disk offset. This means that lookup comparisons are only done with: (physical block, owner, offset) This means that queries can return incorrect results. On consistent filesystems this hasn't been an issue because blocks are never shared between forks or with bmbt blocks; and are never unwritten. However, this bug means that online repair cannot always detect corruption in the key information in internal rmapbt nodes. Found by fuzzing keys[1].attrfork = ones on xfs/371. Fixes:4b8ed67794("xfs: add rmap btree operations") Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.